Polyphenylene ether resin, composition and preparation method and application thereof

Abstract

The invention discloses a polyphenylene ether resin, a composition and a preparation method and application thereof, the total mass concentration of other elements except carbon, hydrogen and oxygen in the polyphenylene ether resin is less than or equal to 1000ppm, and the mass concentration of nitrogen is less than or equal to 200ppm. By controlling the content of the N element and other impurity elements in the polyphenylene ether resin, the increase of the yellow index after the resin composition is extruded is inhibited, the product appearance of the polyphenylene ether resin composition is improved, and the heat resistance and mechanical property of the resin composition are improved.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of polyphenylene ether resin, and in particular to a polyphenylene ether resin, a composition, a preparation method and application thereof. Background Art

[0002] Polyphenylene ether, also known as polyphenylene oxide, is one of the five major engineering plastics, and its modified products are widely used in 5G, electronic appliances, photovoltaics, new energy vehicle batteries and other material fields. Thanks to the rigid structure of polyphenylene ether, it has high heat stability and excellent mechanical properties. Due to the lack of polar groups in the main chain, it also has excellent dielectric properties; the modified polyphenylene ether resin composition is widely used as a structural part in the fields of household electrical control housings, photovoltaic junction boxes, chip trays, etc.

[0003] The polymerization process of polyphenylene ether determines that there are a variety of small molecule residues in its resin products, including solvents, catalysts and other small molecules. These small molecule residues will induce the production of oxidized groups at the ends of the polyphenylene ether chains under high temperature and high shear conditions during the subsequent modification of the polyphenylene ether resin, causing the product color to darken. At the same time, it will induce the degradation of the molecular chain, further affecting the heat resistance of the product, as well as the mechanical properties and dielectric properties of the long-term use.

[0004] At present, for the discoloration problem, the conventional method is to introduce antioxidants and other substances that can inhibit discoloration, thereby reducing the yellow index of polyphenylene ether. For example: Chinese patent application CN101423658A discloses a method for preparing a polyphenylene ether resin composition, by introducing an organic silicon element polymer and a compatibilizer of maleic anhydride with polar groups during the modification process to inhibit the discoloration problem of the polyphenylene ether resin composition during processing; the resin composition and molded product disclosed in Chinese patent application CN111164155, wherein by adding phenolic antioxidants / phosphorus antioxidants / amine antioxidants, the color tone is not easily changed even when placed at high temperature for a long time; the above-mentioned method of introducing antioxidants and other substances that can inhibit discoloration to form a resin composition, although the discoloration is alleviated, the same mechanical properties such as bending modulus are reduced, and the introduction of polar groups is not conducive to improving the heat resistance of the resin composition. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is that the means currently disclosed for reducing the discoloration of polyphenylene ether have defects that are not conducive to mechanical properties and heat resistance, and thus a polyphenylene ether resin, composition, preparation method and use thereof are provided to solve the above problems.

[0006] A polyphenylene ether resin, the total mass concentration of other elements except carbon, hydrogen and oxygen is ≤1000ppm, and the mass concentration of nitrogen is ≤200ppm. For example: the total mass concentration of other elements except carbon, hydrogen and oxygen is ≤1000ppm, ≤800ppm, ≤500ppm, ≤400ppm, ≤300ppm, ≤200ppm, ≤100ppm, etc.

[0007] In an embodiment of the present invention, the mass concentration of nitrogen is ≤100 ppm;

[0008] And / or, the total mass concentration of metal elements is ≤1 ppm, preferably ≤0.3 ppm.

[0009] In one embodiment of the present invention, the intrinsic viscosity is 0.20-0.90 dL / g, preferably 0.30-0.60 dL / g; for example: the intrinsic viscosity is 0.20 dL / g, 0.3 dL / g, 0.4 dL / g, 0.5 dL / g, 0.6 dL / g, 0.7 dL / g, 0.8 dL / g, 0.9 dL / g, etc.

[0010] and / or, using polystyrene as the standard, the number average molecular weight M measured by gel permeation chromatography n 5000-60000g / mol, weight average molecular weight M w 7000-110000, 1.4 <M w / M n <2.1. For example: number average molecular weight M n is 5000 g / mol, 10000 g / mol, 15000 g / mol, 20000 g / mol, 30000 g / mol, 40000 g / mol, 50000 g / mol, 60000 g / mol, etc., and the weight average molecular weight M w 7000, 10000, 15000, 20000, 25000, 30000, 40000, 50000, 60000, 80000, 100000, 110000, etc., M w / M n They are 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, etc.

[0011] In one embodiment of the present invention, the structure of the polyphenylene ether resin is shown in formula (I):

[0012]

[0013] In the above formula (I), R1, R2, R3, and R4 groups can independently be H, C m H 2m+1 , Cm H p X q 、 C m H p O q 、 phenyl, alkylphenyl, alkoxyphenyl, haloaryl, alkenyl, alkynyl; where 1 < m < 12, p + q = 2m + 1, and X is one of F, Cl, Br;

[0014] 50 < n < 500;

[0015] Preferably, R1 and R2 are CH3, and R3 and R4 are H, that is, the polyphenylene ether resin is poly(2,6-dimethylphenyl) ether.

[0016] In the present invention, it is found that higher contents of Cu and N impurities can lead to large changes in the yellowness index before and after extrusion, and poor heat resistance and mechanical properties under high-temperature aging. Therefore, by simply controlling the contents of Cu and N impurities in the product and the total mass concentration of other elements except C, H, and O within a specific range, especially controlling the mass concentration of nitrogen element within a specific range, the heat resistance of the resin composition and its mechanical properties under high-temperature aging can be improved while reducing the change in the yellowness index before and after extrusion. There are various methods to control the impurity content range in the polyphenylene ether resin, and any method that can control the contents of Cu and N impurities in the product and the total mass concentration of other elements except C, H, and O within a specific range can be applied, including but not limited to the methods already disclosed in the prior art or the methods improved on the basis of the prior art.

[0017] The following provides one method that can control the impurity content range in the polyphenylene ether resin within the required range of the present invention. Specifically, the present invention also provides a method for preparing a polyphenylene ether resin, including:

[0018] Oxidative polymerization to obtain a polyphenylene ether resin solution;

[0019] Post-treatment: Under the condition that the temperature is higher than the polymerization temperature, mix and stir the polyphenylene ether resin solution with a ligand compound of a metal ion, and then obtain an organic solution through liquid-liquid separation and washing with water;

[0020] Obtaining a solid polymer: Mix the organic solution with its poor solvent to obtain a resin semi-finished product in solid form;

[0021] Devolatilization: Remove small molecules from the resin semi-finished product to obtain a polyphenylene ether resin with a total mass concentration of other elements except C, H, and O ≤ 1000 ppm and a mass concentration of nitrogen element ≤ 200 ppm.

[0022] In one embodiment of the present invention, the oxidative polymerization process comprises: mixing a phenolic compound, an organic amine compound, a metal compound and a good solvent, introducing an oxygen-containing gas, and performing an oxidative polymerization reaction to obtain a polyphenylene ether resin solution; preferably, the metal compound is obtained by reacting an aqueous solution of hydrogen halide with a metal oxide;

[0023] and / or, the ligand compound of the metal ion includes at least one of hydrochloric acid, acetic acid, ethylenediaminetetraacetic acid salt, oxalic acid tetraacetic acid trisodium salt, oxalic acid tetraacetic acid tetrapotassium salt, ethylenediaminetetraacetic acid tetrasodium salt, and nitrilotriacetic acid trisodium salt;

[0024] and / or, the treatment temperature in the post-treatment step is 40-75°C;

[0025] And / or, the amount of deionized water added in the post-treatment step is greater than 0.7% of the organic solvent content.

[0026] In one embodiment of the present invention, the structure of the phenolic compound is as shown in formula (II):

[0027] The phenolic compound is preferably 2,6-dimethylphenol;

[0028] And / or, the organic amine compound comprises one or more of a diamine compound, a monotertiary amine compound, and a monosecondary amine compound, wherein the diamine compound is selected from one or more compounds having the general structural formula shown in formula (III);

[0029] Among them, R5 is C n H 2n , n≥2; R6, R7, R8, R9 each independently represent H, C m H 2m+1 , and m≥2, R6, R7, R8, and R9 have at most 2 H at the same time; the organic amine compound is preferably at least two of N,N-diisopropylethylenediamine, di(4-tert-butylphenyl)amine, N,N-dimethyl-n-pentylamine, and dimethylbutylamine.

[0030] And / or, the metal ion in the metal compound is Cu x+ , anion is selected from Br - , Cl - , azide, organic carboxylate; x = 1 or 2, the anion is preferably Br - or Cl - ; The metal compound is preferably cuprous bromide.

[0031] The present invention also provides a resin composition, comprising the polyphenylene ether resin or the polyphenylene ether resin prepared by the above method.

[0032] In one embodiment of the present invention, the resin composition further comprises other plastics besides the polyphenylene ether resin, and the other plastics are preferably one or more of high impact polystyrene (HIPS), styrene copolymer (PS), and polypropylene (PP).

[0033] The invention also provides application of the resin composition in household appliances.

[0034] The technical solution of the present invention has the following advantages:

[0035] The present invention provides a polyphenylene ether resin. By controlling the content of other residual impurity elements except carbon, hydrogen and oxygen in the polyphenylene ether resin, specifically, by controlling the total mass concentration of other elements except carbon, hydrogen and oxygen to be ≤1000ppm and the mass concentration of nitrogen to be ≤200ppm, the yellowness index of the polyphenylene ether resin before and after modified extrusion changes little, the heat resistance of the resin composition is improved, and the mechanical properties under high temperature aging are improved. DETAILED DESCRIPTION

[0036] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0037] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0038] The sources of raw materials used in the following examples and comparative examples are as follows:

[0039] 2,6-Dimethylphenol, Nantong Xingchen Synthetic Materials Co., Ltd., purity >99.99%;

[0040] N,N-diisopropylethylenediamine, Shanghai Longsheng Chemical Co., Ltd., purity>98%;

[0041] Di(4-tert-butylphenyl)amine, Beijing Huawei Ruike Chemical Technology Co., Ltd., purity>98%;

[0042] Dimethylbutylamine, Tianmen Hengchang Chemical Co., Ltd., purity >98%;

[0043] Cuprous oxide, Zhejiang Yamei Nanotechnology Co., Ltd., purity >98%;

[0044] Toluene, Shandong Zhengxing New Materials Co., Ltd., purity >99%;

[0045] Methanol, Shandong Hexun Energy Technology Co., Ltd., purity >99%;

[0046] Chloroform, Yonghua Chemical Co., Ltd., purity >98%;

[0047] 47% HBr, Weifang Huitao Chemical Co., Ltd., purity>98%;

[0048] Nitrilotriacetic acid trisodium salt, Jinan Century Tongda Chemical Co., Ltd., purity >98%;

[0049] Ethylenediaminetetraacetic acid tetrasodium salt, Shandong Chuangying Chemical Co., Ltd., purity >98%.

[0050] Example 1

[0051] A method for preparing a polyphenylene ether resin, comprising:

[0052] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0053] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 1700 g of deionized water, stand for stratification, and repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0054] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0055] The polyphenylene ether resin prepared above is blended with high impact polystyrene (HIPS) and polypropylene (PP) in a mass ratio of 50:50:10 for extrusion modification. The extrusion conditions are: a barrel temperature of 310°C, a screw speed of 250rpm, and a vacuum degassing of -650mmHg. The blending is carried out to prepare a modified polyphenylene ether resin composition. After extrusion modification, a resin composition is obtained, and a product is obtained by injection molding the resin composition.

[0056] Example 2

[0057] A method for preparing a polyphenylene ether resin, comprising:

[0058] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0059] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 1700 g of deionized water, stand for stratification, and repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0060] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 40° C., solid-liquid separation was performed, and the mixture was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0061] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0062] Example 3

[0063] A method for preparing a polyphenylene ether resin, comprising:

[0064] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 39.4 g (0.27 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0065] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 1700 g of deionized water, stand for stratification, and repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0066] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0067] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0068] Example 4

[0069] A method for preparing a polyphenylene ether resin, comprising:

[0070] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0071] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 70±1° C. for 90 min, add 1700 g of deionized water, stand for stratification, and repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0072] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0073] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0074] Example 5

[0075] A method for preparing a polyphenylene ether resin, comprising:

[0076] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0077] Add 333 g (0.03 mol / L) of EDTA·4Na aqueous solution to the polyphenylene ether resin solution, stir at 65±1°C for 90 min, add 1700 g of deionized water and allow to stand for stratification, repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0078] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0079] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0080] Example 6

[0081] A method for preparing a polyphenylene ether resin, comprising:

[0082] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0083] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 3400 g of deionized water, and allow to stand for stratification. Repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed.

[0084] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0085] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0086] Example 7

[0087] A method for preparing a polyphenylene ether resin, comprising:

[0088] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 40 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0089] Add 167 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1°C for 90 min, add 3400 g of deionized water, let stand for stratification, repeat the operation once, and obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0090] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0091] The polyphenylene ether resin prepared above was used in the same process as in Example 1 to prepare a resin composition and a product.

[0092] Comparative Example 1

[0093] A method for preparing a polyphenylene ether resin, comprising:

[0094] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0095] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 1700 g of deionized water, stand for stratification, and repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed;

[0096] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 25°C, solid-liquid separation was performed, and the toluene solution was washed three times with methanol that was 50% by mass to obtain a wet solid polyphenylene ether, which was then vacuum dried at 120°C to obtain a polyphenylene ether resin.

[0097] Comparative Example 2

[0098] A method for preparing a polyphenylene ether resin, comprising:

[0099] 5000 g (40.93 mol) of 2,6-dimethylphenol, 20000 g of toluene, 8.2 g (0.05 mol) of N,N-diisopropylethylenediamine, 78.8 g (0.28 mol) of di(4-tert-butylphenyl)amine, 351.77 g (0.52 mol) of dimethylbutylamine, 32.2 g (0.17 mol) of HBr and 3.25 g (0.017 mol) of Cu2O were reacted to obtain a CuBr (0.033 mol) solution, which was added to a 50 L reactor with a stirring device, oxygen was introduced at a flow rate of 8.33 L / min, polymerization was started at 35±0.5° C., and after polymerization for 60 min, oxygen introduction was stopped to obtain a polyphenylene ether resin solution;

[0100] Add 333 g (0.03 mol / L) of an aqueous solution of trisodium nitrilotriacetate to the polyphenylene ether resin solution, stir at 65±1° C. for 90 min, add 800 g of deionized water, and allow to stand for stratification. Repeat the operation once to obtain a toluene solution from which copper ions and nitrogen elements have been removed.

[0101] The toluene solution and methanol were mixed at a mass ratio of 1:1 at 55° C., the solid-liquid separation was performed, and the solution was washed three times with methanol in an amount of 50% by mass of the toluene solution to obtain a solid polyphenylene ether with a moisture content. After vacuum drying at 120° C., a polyphenylene ether resin was obtained.

[0102] The polyphenylene ether resins prepared in the above examples and comparative examples were tested for Cu content, N content, number average molecular weight and intrinsic viscosity.

[0103] Among them, the content of metal elements such as Cu was tested by AES-ICP; the N element was tested by an element analyzer, instrument manufacturer: German Elements (imported), instrument model: vario EL Cube; the number average molecular weight was determined by size exclusion gel chromatography using PS with Mn of 500-500000 and molecular weight distribution of 1.00 for pre-calibration, instrument manufacturer: Agilent Technologies, chromatographic column model: PLgel5μm The intrinsic viscosity is tested by Ubbelohde viscometer, instrument manufacturer: Hangzhou Zhuoxiang Technology Co., Ltd., instrument model: AVM-4.

[0104] The test results of the above test are shown in Table 1 below.

[0105] Table 1

[0106]

[0107] Among the elements other than carbon, hydrogen and oxygen, except Cu and N, the contents of other elements are less than 1 ppm and cannot be detected. Therefore, the total mass concentration of other elements except carbon, hydrogen and oxygen in the embodiments of the present invention and the comparative examples is ≤1000 ppm.

[0108] The products prepared in various embodiments and comparative examples were used to test the changes in bending modulus, heat deformation temperature and yellowness index;

[0109] The flexural modulus was measured according to ASTM D-790 using a 0.32 cm thick narrow strip molded sheet under the test conditions of a test speed of 3 mm / min and a support distance of 101.6 mm.

[0110] Heat deformation temperature test method: Apply the required load (1.82MPa) to the specimen, then immerse the specimen in silicone oil, preheat for 3 to 5 minutes, and heat the oil at a rate of 2℃ / min. Measure the temperature when the specimen sags to 0.254mm.

[0111] Yellowness index change ΔYI: Measure the yellowness index Y1 of the polyphenylene ether resin, measure the yellowness index Y2 of the resin composition, and use Y2-Y1 to get the yellowness index change YI. After at least three measurements, the average value ΔYI is the yellowness index change. The yellowness index adopts the ASTM E313 standard.

[0112] The test results of the above test are shown in Table 2 below.

[0113] Table 2

[0114] Flexural modulus, MPa Heat deformation temperature 1.82Mpa, 3.2mm Yellowness index change ΔYI Example 1 2082 116 2.25 Example 2 2075 115 2.32 Example 3 2084 121 2.22 Example 4 2079 118 2.19 Example 5 2074 122 2.25 Example 6 2080 116 2.29 Example 7 2074 105 3.69 Comparative Example 1 2071 109 4.51 Comparative Example 2 2069 110 4.27

[0115] The mass concentration of nitrogen in the polyphenylene ether resin will significantly affect the stability of the yellow index of the polyphenylene ether resin product after extrusion, and will also affect the thermal and mechanical properties of the product. Therefore, by controlling the total mass concentration of other elements except carbon, hydrogen and oxygen to ≤1000ppm and the mass concentration of nitrogen to ≤200ppm, the yellow index of the resin composition after extrusion can be effectively suppressed, and the heat resistance and mechanical properties of the resin can be improved.

[0116] Specifically, it can be seen from the data in Table 2 combined with Table 1 that the yellowness index of the resin composition in Comparative Examples 1 and 2 is significantly increased compared with the resin before extrusion. The reason may be that the N element is residual, and the small molecules such as organic amines represented are residual. The N residue will promote the oxidation of the terminal hydroxyl groups of the polyphenylene ether, resulting in the yellowness index of the resin composition being increased by more than 4 compared with the resin before extrusion. By controlling the mass concentration of the N element ≤ 200ppm, the increased yellowness index can be reduced to less than 4. When the mass concentration of the N element is ≤ 100ppm, the increased yellowness index can be reduced to about 2, significantly reducing the change of the yellowness index before and after extrusion. At the same time, the bending modulus in Comparative Examples 1 and 2 is also reduced by about 10Mpa compared with Example 1, and the heat deformation temperature is also reduced by about 5°C. It is speculated that the high residual N element may cause the polyphenylene ether resin to undergo segment degradation caused by small molecules under the high temperature environment of extrusion, resulting in a reduction in thermal and mechanical properties.

[0117] In summary, controlling the contents of N and Cu in the polyphenylene ether resin is beneficial to suppressing the increase of the yellow index of the resin composition after extrusion, thereby improving the product appearance of the polyphenylene ether resin composition, and improving the heat resistance and mechanical properties of the resin composition.

[0118] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A polyphenylene ether resin, characterized in that The total mass concentration of elements other than carbon, hydrogen and oxygen is ≤1000ppm, and the mass concentration of nitrogen is ≤200ppm.

2. The polyphenylene ether resin according to claim 1, characterized in that The mass concentration of nitrogen is ≤100ppm; And / or, the total mass concentration of metal elements is ≤1 ppm, preferably ≤0.3 ppm.

3. The polyphenylene ether resin according to claim 1 or 2, characterized in that The intrinsic viscosity is 0.20-0.90 dL / g, preferably 0.30-0.60 dL / g; and / or, using polystyrene as the standard, the number average molecular weight M measured by gel permeation chromatography n 5000-60000g / mol, weight average molecular weight M w 7000-110000, 1.4 <M w / M n <2.

1.

4. The polyphenylene ether resin according to any one of claims 1 to 3, characterized in that Its structure is shown in formula (I), The groups R1, R2, R3, and R4 can independently be H, C m H 2m+1 , C m H p X q , C m H p O q , phenyl, alkylphenyl, alkoxyphenyl, haloaryl, alkenyl, alkynyl; where 1 < m < 12, p + q = 2m + 1, and X is one of F, Cl, Br; 50<n<500； Preferably, R1 and R2 are CH3, and R3 and R4 are H.

5. A method for preparing a polyphenylene ether resin, characterized in that: include: Oxidative polymerization to obtain a polyphenylene ether resin solution; Post-treatment: mixing and stirring the polyphenylene ether resin solution and the ligand compound of the metal ion at a temperature higher than the polymerization temperature, and then washing with water to obtain an organic solution; Obtaining solid polymer: Mixing the organic solution with its poor solvent to obtain a solid resin semi-finished product; Devolatilization: The resin semi-finished product is subjected to small molecule removal to obtain a polyphenylene ether resin having a total mass concentration of elements other than carbon, hydrogen and oxygen of ≤1000ppm and a mass concentration of nitrogen of ≤200ppm.

6. The method according to claim 5, characterized in that The oxidative polymerization process comprises: mixing a phenolic compound, an organic amine compound, a metal compound and a good solvent, introducing an oxygen-containing gas, and performing an oxidative polymerization reaction to obtain a polyphenylene ether resin solution; preferably, the metal compound is obtained by reacting an aqueous solution of hydrogen halide with a metal oxide; and / or, the ligand compound of the metal ion includes at least one of hydrochloric acid, acetic acid, ethylenediaminetetraacetic acid salt, oxalic acid tetraacetic acid trisodium salt, oxalic acid tetraacetic acid tetrapotassium salt, ethylenediaminetetraacetic acid tetrasodium salt, and nitrilotriacetic acid trisodium salt; and / or, the treatment temperature in the post-treatment step is 40-75°C; And / or, the amount of deionized water added in the post-treatment step is greater than 0.7% of the organic solvent content.

7. The method according to claim 6, characterized in that The structure of the phenolic compound is shown in formula (II), The phenolic compound is preferably 2,6-dimethylphenol; And / or, the organic amine compound comprises one or more of a diamine compound, a monotertiary amine compound, and a monosecondary amine compound, wherein the diamine compound is selected from one or more compounds having the general structural formula shown in formula (III); Among them, R5 is C n H 2n , n≥2; R6, R7, R8, R9 each independently represent H, C m H 2m+1 , and m≥2, R6, R7, R8, and R9 have at most 2 H at the same time; the organic amine compound is preferably at least two of N,N-diisopropylethylenediamine, di(4-tert-butylphenyl)amine, N,N-dimethyl-n-pentylamine, and dimethylbutylamine; And / or, the metal ion in the metal compound is Cu x+ , anion is selected from Br - , Cl - , azide, organic carboxylate; x = 1 or 2, the anion is preferably Br - or Cl - ; The metal compound is preferably cuprous bromide.

8. A resin composition, characterized in that The invention comprises the polyphenylene ether resin according to any one of claims 1 to 4, or the polyphenylene ether resin prepared by the method according to any one of claims 5 to 7.

9. The resin composition according to claim 8, characterized in that Other plastics besides polyphenylene ether resin are also included, and the other plastics are preferably one or more of HIPS, PS, and PP.

10. Use of the resin composition according to claim 8 or 9 in household appliances.

Images